Filling-tube construction for providing a connection between a mould to be filled with molten metal and a mould-filling furnace

ABSTRACT

In a filling-tube construction ( 1, 2 ) for providing a connection between a mould ( 6 ) to be filled with molten metal and a mould-filling furnace ( 3 ) containing molten metal ( 5 ), said mould ( 6 ) having at least one casting cavity ( 7 ), the lowermost part of each such cavity communicating with a filling duct ( 8 ), at least one end of which is open to the outside of said mould ( 6 ) and adapted to be temporarily connected to the filling-tube construction ( 1, 2 ) to receive molten metal ( 5 ) from the mould-filling furnace ( 3 ), the mould-filling furnace being adapted to contain molten metal ( 5 ) and to transfer said molten metal ( 5 ) under a controlled pressure through the filling-tube construction ( 1, 2 ) and to the filling duct ( 8 ), the filling-tube construction comprises a first section ( 1 ) extending from a position close to the bottom of said mould-filling furnace ( 3 ) up to an intermediate position closer to the filling duct ( 8 ) and at least one separate second section ( 2 ) providing a connection from the upper end of the first section ( 1 ) to the open end of the filling duct ( 8 ) and adapted to provide a fluid-tight connection to the upper end of the first section ( 1 ) and the open end of the filling duct ( 8 ). In this way an easy adjustment and/or exchange of parts of the filling-tube constructions can be provided by simply adjusting and/or exchanging the second section ( 2 ), without disassembly of the connection between the first section ( 1 ) and the mould-filling furnace ( 3 ). The invention also includes a method of modifying a conventional constructed filling tube to a filling tube as described above.

TECHNICAL FIELD

[0001] The present invention relates to a filling-tube construction ofthe kind set forth in the preamble of claim 1.

BACKGROUND ART

[0002] In filling-tube constructions of this kind it is known to providea filling tube in one piece extending from a position close to thebottom of the mould-filling furnace to a filling head, which isconnectable to the open end of the filling duct. A construction of thiskind is e.g. known from WO 99/00202. When using a filling tube of thiskind, the adjustment of its position relative to the mould, especially amould in a mould string, is relatively complex involving the looseningof the fixation of the complete filling tube to the mould-fillingfurnace, in order to adjust the position and angle of the filling-tubehead relative to the mould surface to be connected thereto in a sealingway. Normally the filling-tube construction comprises a bend in order toprovide a suitably short construction and a suitable connection to theopen end of the filling duct, said bend giving rise to problems, whenthe filling tube has to be cleaned from contaminants, such as oxidationproducts. Furthermore, when different types of filling heads are to beused, the whole filling-tube construction will have to be replaced inorder to provide a new type of filling head for connecting to a new typeof mould.

[0003] From EP-A-0 956 916 it is known to solve the cleaning andexchange problems by having the filling tube split up in two or moresections. However, these sections do not provide any adjustmentpossibilities for the position and angle of the filling-tube headrelative to the mould surface.

[0004] From EP-A-0 976 476 it is known to provide an angular movabilityof the filling tube by having the filling tube connected to the fillingfurnace through a cardan connection. The purpose of this cardanconnection is to allow a certain tilting of the mould while connected tothe filling tube, and not to provide any form of adjustment.Furthermore, the whole filling-tube construction is moved as one unitwithout any possibilities of moving one part of the filling tuberelative to the other one.

DISCLOSURE OF THE INVENTION

[0005] It is the object of the present invention to provide afilling-tube construction of the kind referred to above, with which itis possible to avoid the difficulties explained above, and this objectis achieved with a filling-tube construction of said kind, whichaccording to the present invention also comprises the features set forthin the characterising clause of claim 1. With this arrangement thefilling-tube construction is split up into two parts, thereby providingan easy possibility of adjusting the position and angle of the secondsection without disassembly of the connection between the first sectionand the mould-filling furnace.

[0006] Further advantageous embodiments of the filling-tubeconstruction, the effects of which will be evident from the followingdetailed part of the present description, are set forth in thesubordinate claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In the following detailed part of the present description, theinvention will be explained in more detail with reference to theexemplary embodiment of a filling-tube construction according to theinvention shown in the drawing, in which FIG. 1 schematically shows afilling-tube construction in accordance with the present inventionmounted to provide a connection between a mould-filling furnace and amould.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The filling-tube construction schematically shown in FIG. 1comprises a first section 1 extending from a position close to thebottom of the mould-filling furnace 3 and a second section 2 providing aconnection from the upper end of the first section 1 to the open end ofthe filling-duct 8 in the mould 6. The filling-tube construction 1, 2provides a connection for filling the casting cavity 7 in the mould 6with molten metal 5, e.g. aluminium alloys, cast iron, etc. from themould-filling furnace 3, said filling being provided by setting themould-filling furnace 3 under pressure, whereby molten metal 5 from themould-filling furnace 3 will be transferred from the mould-fillingfurnace 3 to the casting cavity 7 through the restriction 4, the firstsection 1, the second section 2 and the filling duct 8. The firstsection 1 is relatively fixedly connected to the mould-filling furnace 3and the part of the first section 1 extending out of the mould-fillingfurnace 3 is surrounded by a bellow 10 and a heating wire 11 for keepingthe first section at an elevated temperature. The second section 2 isformed as a ball, connected fluid-tight to the upper end of the firstsection 1, said fluid-tight connection being provided by the formationof a chamfer 12 on the upper end of the first section 1, possiblysupplemented by a “fluid gasket”, e.g. in the form of thick-flowingboron nitrate.

[0009] The second section 2 can thus be adjusted by moving the ball inthe chamfer 12 on the upper end of the first section 1 and the secondsection 2 can be fixed in the adjusted position by means of a fitting 9pressing the second section 2 against the first section 1. The secondsection 2 comprises a planar surface for providing the fluid-tightconnection to the open end of the filling duct 8 and the aboveadjustment of the second section 2 is performed in order to provide asecure fluid-tight connection between the second section 2 and thesurface of the mould 6. The outlet from the second section 2 forms anangle of approximately 95° with the planar surface, thereby allowingsuperfluous metal 5 to flow back to the mould-filling furnace 3 afterfilling of the casting cavity 7. Before this flow back of molten metal5, the filling duct 8 is closed by a plate 13 moved into the fillingduct 8 in a manner not shown, or other means for closing the fillingduct 8 are used, e.g. as described in EP 760.723.

[0010] Adjustment or exchange of the second section can easily beperformed by loosening or dismounting the fitting 9 respectively. Thematerial of the first and second section 1 and 2 will naturally have tobe high temperature resistant in accordance with the temperature of themolten metal 5 to be transferred from the mould-filling furnace 3 to thecasting cavity 7. High temperature resistant materials for thesecomponents are e.g. ceramic materials, graphite materials, refractorycement materials, alutitanate, coated refractory cement, said coatingpossibly being boron nitrate, ceramic wool coated by a suitablematerial, e.g. Fiberfax or boron nitrate, or combinations thereof.

[0011] The restriction 4 at the bottom of the first section 1 isprovided in order to reduce the turbulence in the molten metal flowingback into the mould-filling furnace 3 and reduce the effect of pressurefluctuations due to wave movements in the mould-filling furnace, whenthe second section 2 is removed from the surface of the mould 6.

[0012] Existing filling-tube constructions can be modified into afilling-tube construction in accordance with the present invention byperforming the following steps:

[0013] a) cutting-off the existing tube at an appropriate position, e.g.immediately below the bend,

[0014] b) providing a chamfer 12 at the top of the cut-off tube,

[0015] c) fitting a second section 2, e.g. a ball 2, fitting in saidchamfer at the upper end of the tube 1,

[0016] d) fixing said second section 2 by means of a fitting 9 pressingthe second section 2 against the first section 1, and possibly

[0017] e) incorporating a restriction 4 at the bottom end of the tube 1.

[0018] Above, the present invention has been explained in connectionwith preferred embodiments relating to a filling-tube construction.However, several modifications will be evident within the scope of thefollowing claims, such modifications comprising formation of the secondsection 2 with an other configuration for providing the fluid-tightconnection to the filling duct 8 and a different connection between thefirst section 1 and second section 2, etc.

1. Filling-tube construction (1, 2) for providing a connection between amould (6) to be filled with molten metal and a mould-filling furnace (3)containing molten metal (5), said mould (6) having at least one castingcavity (7), the lowermost part of each such cavity communicating with afilling duct (8), at least one end of which is open to the outside ofsaid mould (6) and adapted to be temporarily connected to thefilling-tube construction (1, 2) to receive molten metal (5) from themould-filling furnace (3), the mould-filling furnace (3) being adaptedto contain molten metal (5) and to transfer said molten metal (5) undera controlled pressure through the filling-tube construction (1, 2) andto the filling duct (8), said filling-tube construction comprising afirst section (1) extending from a position close to the bottom of saidmould-filling furnace (3) up to an intermediate position closer to thefilling duct (8) and at least one separate second section (2) providinga connection from the upper end of the first section (1) to the open endof the filling duct (8) and adapted to provide a fluid-tight connectionto the upper end of the first section (1) and the open end of thefilling duct (8), characterized by the fluid-tight connection betweenthe first and second section providing a movability of the secondsection (2) relative to the first section (1).
 2. Filling-tubeconstruction in accordance with claim 1, characterized by the firstsection (1) being a straight tube without bends.
 3. Filling tube inaccordance with claim 2, characterized by said movability being providedin the form of a ball joint (12).
 4. Filling tube in accordance withclaim 3, characterized by said ball joint (12) comprising the formationof a chamfer on the upper end of the first section (1) and forming thesecond section as a ball (2) fitting in said chamfer.
 5. Filling tube inaccordance with any of the preceding claims, characterized by the secondsection (2) comprising a planar surface for providing the fluid-tightconnection to the open end of the filling duct (8).
 6. Filling tube inaccordance with claim 5, characterized by the outlet from the secondsection (2) forming an angle of approximately 95° with said planarsurface.
 7. Filling tube in accordance with any of the preceding claims,characterized by the second section (2) being connected to the firstsection (1) by means of a fitting (9) pressing the second section (2)against the first section (1).
 8. Filling tube in accordance with claim7, characterized by said fitting (9) being adapted to be loosened inorder to enable adjustment of the position of the second section (2). 9.Filling tube in accordance with any of the preceding claims,characterized by said first section (1) being formed of a hightemperature resistant material, e.g. a ceramic material, a graphitematerial, a refractory cement material or combinations thereof. 10.Filling tube in accordance with any of the preceding claims,characterized by said second section (2) being formed of a materialselected from alutitanate, coated refractory cement, said coatingpossibly being boron nitrate, ceramic wool coated by a suitablematerial, e.g. Fiberfax or boron nitrate.
 11. Filling tube in accordancewith any of the preceding claims, characterized by said fluid-tightconnection between said first and second section being secured by use ofa “fluid gasket” in the form of e.g. thick-flowing boron nitrate. 12.Filling tube in accordance with any of the preceding claims,characterized by comprising a restriction (4) at the bottom of the firstsection (1).
 13. Method of modifying a filling tube of conventionalconstruction into a filling tube in accordance with any of the precedingclaims, characterized by comprising the following steps: a) cutting-offthe existing tube at an appropriate position, b) providing a chamfer(12) at the top of the cut-off tube, c) fitting a second section (2) inaccordance with claim 5 to the upper end of the tube (1), and d) fittingsaid second section (2) using a fitting (9) in accordance with claim 8.14. Method in accordance with claim 13, characterized by furthercomprising the step of e) incorporating a restriction (4) at the bottomend of the tube (1).